Carburetor



Dec. 21 1926.

s. SYKES ET'AL CARBURETOR Filed June '7, 1923 2 Sheets-Sheet 1 ATTORNEYSDec. 21,1926. 1 1,611,792

s. sYKEs ET Al.

GARBURETOR Filed June' v, 1923 2 sheets-'sheet' a ATTORNEYS WITNEssEsINVENToR Y .SYKL'S (j m v @.SYKES l BY Patented Bec 211, 192e?.

aura srafr STANLEY SYKES AlTD GUY SYKES, OF FLAGSTAFF, ARZONA.

CARBURETOR.

Application filed fune This invention relates to improvements ininternal combustion engines, and has particular reference to acarburetor therefor.

An object of the invention is to provide an improved carburetor ofsimple and practical construction, wherein the mixture of the fuel andair in the mixing chamber is automatically controlled by the operationof the throttle which regulates the speed of the engine.

Another object is to Provide a simple and effective means forautomatically operating the needle valve to control the amount of fuelto be supplied to the mixing chamber.

Ehe above and other objects will appear more clearly from the followingdetail description, `when talren in connection With the accompanyingdrawings, which illustrate a preferred embodiments of the inventiveidea.

ln the drawings- Figm'e 1 is a fragmentary side elevation of thecarburetor constructed in accordance with the invention;

Figure 2 is a fragmentary top plan view;

Figure 3 is a longitudinal section through the mixing chamber;

Figure 41 is an elevational viejv, partly in section, and talren atright angles to `ligure 1; and

Figure 5 is a side elevation of the choke valve employed in connectionWith the invention.

Referring more particularly to the accompanying drawings, the carburetoris shown as comprising a body G to which is connected the float chamber7 having a passage 8 leading therefrom and communicating With thepassage 9 in the body 6, Which latter passage is controlled by theneedle valve 10. Communicating` with the passage 9 at a point adjacentthe inner end of the needle valve is an air port 11, the size of whichmay be regulated by a set screw 12 and through which air may enter intothe body of the carburetor to mix With the fuel from the float chamberas the same passes the needle valve and enters the outlet pipe 13. Asshown in Figure 1, this outlet pipe is extended into a section of theexhaust manifold 14 of an engine and terminates in a coil 15 Within saidmanifold, whereby the fuel conveyed through the pipe 1.2 is heated andvaporized upon passing through said coil 15. Also .connected to the coil15 is an inlet pipe 16 which communicates with one end of a passage 17in the body of the carbulaas. serial No. ceases.

retor, the other end of which has connected thereto a nozzle 18 having aplurality of perforations 19 adjacent the free end thereof. Y

rlhe nozzle 18 projects from the body 6 and into the mixing chamber 20at the end of said hamber adjoining t-he'body. Intermediate the ends ofthe mixing chamber the same is provided on opposite sides thereof withair inlet Openings 21 through which air may enter into the chamber tomix with the vaporized fuel emitted from the nozzle 18 through theperferations 19 so as to provide a suable combustible mixture Whichpasses from the mixing chamber into the intake manifold of the engine towhich the plate 22 is secured. Rotatable Within the mixing chamber 2O isa choke valve 23, of substantially cylindrical formation, having one endcut to provide opposed flanges 24 each having an edge thereto disposeddiagonally With respect to the longitudinal axis of the valve andarranged in a plane intersecting the diagonal edge of the other flange,as illustre-.ted in Fig. 5. The valve is provided with an arm 25 whichprojects through the mixing chamber 2O and is movable in a slot 26 sothat the valve may be rotated in the chamber. Each of the flanges 24 ofthe valve cooperates with one of the openings 21 in the mixing chamberand is so formed that a rotation of the valve Within said chamber willcause the opening 21 to be enlarged or decreased according to the amountof air it is desired to have pass into the mixing chamber When theengine is first started or is being run during extremely cold weather.This choke valve 23 utilized as an air adjustment independent of thateffected by the control mechanism presently to be described.

ln order to automatically control the quality of the mixture inaccordance with the speed of the engine, the invention further providesa throttle sleeve 27 which is rotatably mounted upon the mixing chamber20 and to which is connected a throttle rod 28 utilized to controlrotation of the sleeve. lt will, of course, be understood that thisthrottle rod may be controlled in any desired manner to operate thethrottle sleeve 2.7. The sleeve 27 is provided with oppositely disposedopenings 2S) therein, which register With the openings 21 in the mixingchamber, and as the sleeve 27 is rotated about said mixing chamber thesize of the openings 2l will be varied to admit more or less air intosaid chamber. The rotation of the sleeve 27 is also utilized to controlthe size of the aperture With Which the needle valve l() is associated,so that when the throttle is operated to increase the speed of theengine, said sleeve will operate the needle valve to enlarge the openingin the passage 9 through Which the fuel from the float chamber 7 tloivs.It will be understood that in thusoperating the throttle to increase thespeed of the engine, the sleeve 27 will be rotated to enlarge theopenings 2l and thus permit of more air entering the mixing chamber. Themeans for accomplishing the control of the needle valve 10, preferablycomprises a cam 30, formed integrally with one end of the sleeve 2T andengaging a roller 3l carried by the free end of a lever 32, pivoted 33to a bracket 3e forming a part of the body 6. rEhe upper end of theneedle valve l() extends through a suitable opening formed in the leverand is threaded to receive the nuts 35 against one of which a spring 36carried by the bracket Se is engaged to normally force the needle valvedownwardly toward its seat and the lever 32 tovvar'd its normalposition, thus maintaining the roller 3l in engagement with theperiphery of the cam 30. The parts are shoivn in Figure l in thepositions they assume ivhen the throttle is fully opened and the needlevalve l0 is raised to its extreme upper position. lt Will thus be seenthat when the throttle is actuated to decrease the speed of the enginethe sleeve 27 will be rotated in a direction to diminish the size of theopenings 2l and the cam 30 Will likewise be rotated to permit of alowering of the needle valve l() and lever 32 under the influence of thespring 36, thus permitting the needle valve to move toward its seat todiminish the size of the orifice through which the fuel in the passage 9flows.

llVhat is claimed is:

l. ln a carburetor', a body having a fuel orince, a mixing chamberhaving an air opening in each side, a fuel inlet in said chamber andeon'nnunicating With said oriiice, a needle valve controlling theorifice, a choke valve in the form of a hollow cylinder mounted to turnin the mixing chamber for varying the size of the openings thereof, athrottle valve in the form of a sleeve mounted to turn on the Walls ofthe mixing chamber and having an opening in each side adapted toregister With the openings of the mixing chamber, and means foroperating the needle valve from the throttle valve.

2. ln a carburetor, a body having a fuel orifice, a mixing chamberhavingl oppositely arranged air openings in its sides, a fuel inlet insaid chamber and communicating with said orifice, a needle 'valvecontrolling the orifice, a tubular choke valve mounted to turn in themixing chamber and having at one end opposed flanges for varying thesize of the openings of the mixing chamber, each flange having an edgedisposed diagonally with respect to the longitudinal axis, of the valveand arranged in a plane intersecting the diagonal edge of the otherflange, a tubu# lar throttle valve mounted to turn on the Walls of themixing chamber and provided with openings adapted to register with theopenings thereof, and means for operating the needle valve from thethrottle valve.

3. ln a carburetor, a body having a fuel orifice, a needle valvecontrolling the orifice, a lever pivoted to the body and through whichthe valve stem projects, a roller on the free end of the lever, a springsecured to the. body and engaging the valve stem, a mixing chambercommunicating with the fuel orilice, a tubular choke valve mounted toturn in the chamber for varying the size of the openings thereof, asleeve throttle valve mountedL to turn on the Walls of the mixingchamber and having openings adapted to register with the openingsthereof, and a cam on one end of the throttle valve and engaging theroller of said lever.

STANLEY SYKES, GUY SYKES.

